Telephone-exchange system.



C. L. GOODRUM.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION mm) 0c.29.191s.

latcnfed out. 28,1919.

2 WM far: (haw/es Z 'aod/wm UNITED STATES BENT OFFICE CHARLES L. GOODRUM, OF NEW YORK,

COMPANY, INCORPORATED, 015

YORK.

N. Y., AssIGNon r WESTERN ELECTRIC YORK/N. Y., A oonroae'rron on NEW TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. P te ted Oct. 28, 1919.

Application filed December 29, 1916. Serial No. 139,577.

To all 107mm it may concern:

Be it known that 1, CHARLES L. Gooneon,

a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Telephonev tor without releasing the automatic switches employed in making the original connection. after In accordance with this invention, the swltehes are set, an electromagnetic responsive device is automatically connected Y through an auxiliary switching mechanism to a contact of the stepping relay. If at any time thereafter the subscriber desires the attention of .an operator, he causes the operation of the step -Jing relay which completes "the circuit for said electromagnetic responsive device. The stepping relay may be operated by manipulating the finger dial at the calling station.

The electromagnetic responsive device, when actuated, causes the operation of any desired signaling device, such as an alarm bell or a lamp before an operator.

Provision is also made for removing the control of the signaling device when operated from the subscriber and resting it in the operator.

The accompanying drawing shows diagrammatically a connection between two subscribers, the circuits of a connector "switch embodying the principles of this inventionbeing shown in full.

A calling subseribers substation is shown at A, connected through a line finder indicated diagrammatically at 3, and a first selector switch shown at 4 to. the connector switch having brushes 14 and 16. B indicates the substation of a called subscriber.

provide I The invention will be more readily understood tram a consideration of the followmg description of the operation of the system.

When the subscriber at A. removes his receiver from the hook the line finder 3 automatically connects his line to a first selector switch 4. The subscriber now sends with his dial a series of impulses which sets the switch 4 on the terminals leading to the con- .nector switch in whose contact bank termihates the line of the desired subscriber. As

soon thesw'itch 4 has been set a circuit is closed from grounded battery through the retardation coil RC, lower brush of switch 3, substation A, upper brush of switch 3, upper brush of switch 4, through the winding ot the stepping relay SR, to ground. The relay SR is energized and closes a circuit for slow relay 5, from ground, armature and front contact of 'relay SR, through the Winding of relay 5, to battery and ground.

The subscriber now sends av second series of impulses whlch causes the armature of the relay SR to vibrate. Each time relay SR retracts its armature a circuit is closed from ground, armature and back contact of relay'SR, right-hand armature and front contact of relay 5, wire l2,'inner right handarmature and back contact of relay TR, side-switch wiper 9' (position 1), through the winding of the primary magnet PM,-to

battery and ground. .The magnet Pli/Las a result of these-impulses, steps the wipers 14 and 16 to the group of terminals in which the line of the ealled'slihscriber terminates.

A circuit is also closed in parallel-with that of the primary magnet, from ground, armar' ture and back contact of relay SR,'righthand armature and front contact of relay 5, through the winding of slow relay 6, to battery, and ground; Relay 6 closes a circuit, from ground'le'it-hand armature the side-switch escape magnet Em, to battery and ground. The magnet Era. is held energized over this circuit during the sending of the series of impulses. of this series of impulses, however, the cir cuit for relay 6 is maintained open at the and front contact of relay 6, through the winding of At the close back contact and right-hand armature of rei lay SR and relay 6 in deenergizingbreaks at its left-hand arniatureth e circuit for mag-' net Escl, which thereupon,deenergizes and moves the side-switch wipers into their sec ond position. 4

Thesubseriber no-w sends the final series of impulses. Each time'th'at-the relay. SR

is deenergized a-circuit is closed for the sec-' ondarymagnet from ground. armatm-e and back contact of relay SR, right-hand armature and front contact of relay 5, wire 12, v inner right-handarmature and backcontact of relay TR,side-switch wiper 9 (position through the winding of the secondary magnet SM, to battery, and ground.

.The magnet SM sets the brushes of the connector switch on the terminals of the wanted line.

Relay TR locks 11 from rounded battery. 'through its. left h ,armature' and front contact of relay T R, wire 19, front contact and right-hand arma- If the wanted line is busy as a calling line,. I battery will be supplied through the retardation coil of some line finder through brush 16 of the connector switch to wire If busy as a called line, battery will be supplied to wire 2 through the ringing relay RR of the connector switch associated with the wanted line, sideswitch wiper 1'1, and brush 16 of said connector, through a multiple connection to the brush 16 of the connector of the calling line. In either "case a circuit for the; test relay TR .will be completed from battery, brush 16, wire 2, wiper ll, (position 2) righthand winding of relay TR, front contact? and armature of magnet E862, back contact and left-hand armature of relay 6. to ground.

and winding, left-hand ture of relayf5, to ground. Relay TR closes in parallel with this-circuit a locking circuit for-the magnet Em, from ground, right-,-

hand armature and front contact of relay 5,

wire 19, front contact and armature of relay TR, wiper 8 (POSIUOII 2) through the winding of magnet Esa, to battery. andgrol md. I

The continued energization of niagnet disc. will thus prevent the advance or the side switch into its third 1 )osition\\'hen the called line is found busy. Relay TR also closes a circuit from ground through the secondary winding of the transformer B z. outerrighthand armature andfront contact of relay T'R, wire 20, line wire 1. brushes tand 3,

substation A, through the winding of" the' coil BC to battery, andground.

'Th subscriber 1'ecc1ves,.as the result of I this circuit a distinctive busy tone and hangs up his receiver, causing the release of .the switch in a manner to be described.

. Assuming now that the calledsubseribers' line is foundidle, no circuit will be completed for the test relay TR and the magnet Em will, at the conclusion of the last series ator G, Windin armature ant front contact of relay 'RR,

oi'impulses, dener he and advance the slde switch into its thir position. In this position a circuit is completed from battery,

through the winding of ringing relay'RR,

'wiper'il. (position 3), wire2, brush 1G, through thewinding of the called line cut'-' off relay CO, to ground. The relay BB in. attracting its armature completes a circuit for ringing the bell of the called subscriber,

from grounded battery, through the generof the ringing 'trip relay side-switch wiper 10 (position 3), wire 1,

brush 14. substation B, through the winding of the relay CO, to'ground. The ringing trip relay 7 is marginal and will not be energized in this circuit. In'position ,3 of the side switch a circuit forthe magnet B66. was also completed from ground, left-hand: armature and .front contact of relay wire 19, back contact and armature of relay 7, side-switch If, at thistime,---a calling subscriber becomes impatient and desires a connection" with {in-operator, he may, by dialing, .vifbrate thearmatu're' of'the stepping relay SR, which, in retracting its armature, will com plete a circuit from grounc l, armature and back contact of relay SR. right-hand arina;

right-hand armature and back contact of relay CS, ofi'-normal contact'ON, through thewinding of the release rnagnet 'ReL, to "battery and ground. The'release magnet Rel.

is marginal, however, and will not energize It is to, be understood that an alarm bell,

or any other-suitable signah might be sub- 1 stituted for the lalnp'L. The operatorreceiving'the signal inserts a-plug" (not shown) into the jack J and theisubseriber may now converse with'the operator. The-ope'rators signal will beact-uated continuously until by answern'ig' she closes a c rcuit from ground, through the called supervisory. relay CS, wire'l. jack J, operators headset (not in series with the left :winding of'relay 13.

hown) to the wire land throughthe winding of. therelay RR, to battery. and ground. The calledsuperrisoryrelay- 1S energized in this circuit and breaks at its right-hand armature .and' front contact the previously traced locking circuit for the relay 13, which 85 wiper 8 (position 3), through the Winding of magnet Esau, to battery and ground,

sistance of the ringing circuit,previously traced, as to cause the encrgization of the ringing trip relay 7. The ringing trip relay 7, in attracting its armature, breaks at its back contact the locking circuit for the magnet Esau, which, thereupon dei'arergizcs and advances the side switch into its. fourth position. A connection is now complete or conversation betweensubstations A and B, A being supplied through the retardation ,coil RC and the stepping relay SR, while'currcnt for station E is supplied from the called supervisory relay CS and the ringing relay RR. The

' relay CS. will be held. energized until the If, at any time during third. It will be noted called subscriber hangs up.

4 the conversation the calling subscriber desires the attention of an operator, he may, by dialing, cause the energizationof the relay 13 over a circuit which is the same that previously traced with the exception that the side-switch wipert) is in its fourth iglSltlOIl instead of its that the subscriber in so operating his dial will not cause the release of his'switches, since the relay 5 isv made slow enough to remain energized during the vibration of the armature of the stepping relay SR.

At the close of the conversation release of the line finder and selectors may be accomplished by the calli g subscriber alone, but the connector will rtiit be released until both parties have hung up. if the calling subscriber is the first to hang up, the (lei'nieitgization of the relay SR will complete a circuit, previously traced, for energizing slow relay (3. Slow relay 5 is a little faster than slowrelay 6 and will fall oli first, complet-' ing acircuit from ground, at its left-hand armature and back contact 5 through the righthand arn'iature and front contact of relay 6, the front contact and armature of the called supervisory relay CS through the win 2 to therelease magnets of'the line finuer and selector switches. The ground thus applied to the Wire 2 will causethe release ot' the line finder and selector switches in the well-known manner. When both subscribers hang up simultaneously, or the called subscriber is the first to replace his receiver on its hook, ground will be placed on wire 2 from the armature and backcontact of relay SR, right-hand armature and back contact of relay 5, back contact and left-hand armature'of relay US to Wire2, thus closing the release circuit for the linefinder and selector switches. A circuit is also closed from ground, left=hand armature and back contact of relay 5, Wire 15, right hand armature and back Contact of relay CS. oil-normal contact ON, through'the winding of the relcase magnet Rat, to'battery and ground. The placing of a ground on the wire renders the connector switch llllmediatcly selectable, but the return of the switch to normal is insured, since the rclcase magnet is locked up from battery, through its winding, oil-normal contact ON, armature and front contact of magnet Rat, to ground. This locking circuit wvill be broken the restoration of the switch to normal opens contact and the system is in readiness for another call.

Although the invention has been shown applied to switches of thc t\vow'ire multiple trunk type. it is to bc understood that its principles may be readily applied to any well-known typeof automatic switches.

What is claimed is: 1. In a te ephone exchange systen'i, telephone lincs, automatic switches including a connector switch for intcrconnecting said lines, a device for signaling an operator, an

electromagnetic responsive device perma-.

vice, and an auxiliary switching mechanism for opcratively connecting said electromagnetic rcspousive device to said stepping relay when said switches have been set.

3.111 a telephone exchange system, telephone lines, automatic switches including a connector switch for interconm-ctiug said lines, a device for signaling an operator, an

electrmnagnetic responsive device permanently associated with said connector switch for operating said-signalingdevice, means operable by a calling party when a connection has been built up over said switches for actuating said electroniaguctic responsive device, and means for automatically removing control of said electromagnetie responsive device when operated from said calling party'and vesting such control in said operator.

' 4-.ln a telephone exchange system, telephone lines, automatic switches for inter-eon necting said lines, means including a stepping relay for setting Sili &S\VliA'll0H, i'neans operable by a calling pap y for actuating said stepping relay, a device for signaling an operator, an electromagnetic responsive device controlled bysai'd stepping relay for v operating said signaling device, anauxiliary switching mechanism 'for operatively connecting said electromagnetic iresponsive dema'tically removing control of said'electromagnetic responsive device when operated 10 from said calling party and vesting such control in said operator.

In Witness whereof, I hereunto subscribe my name this 28th day of December A. D.,

CHARLES L. GOQDRUM. 

